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3.6 LODA Application Requirements.
You must submit a LODA application to the Civil Aviation Authority (CAA) for your 3.6.1 country. Your CAA must certify that the article has been examined, tested, and found to meet the applicable TSO or the applicable performance standards of the State of Design and any other performance standards the FAA may prescribe to provide an equivalent level of safety to the TSO. Once the CAA determines your LODA application meets all the above mentioned requirements, the authority must make a certifying statement to the FAA that it finds your article meets the TSO and other performance standards the FAA may prescribe (pursuant to § 21.621).
Prior to submitting a LODA application, you should consult the applicable Note:
bilateral agreement to determine if the FAA will issue a LODA to an applicant in your country, or if an alternative process exists.
You must use the applicable TSO that is effective on the date of application for that 3.6.2 article, pursuant to § 21.603. Otherwise, you must ask for an exemption to § 21.603, as outlined in 14 CFR Part 11.
Your LODA application must include (pursuant to § 21.621): 3.6.3 The TSO number for which the approval is requested; 3.6.3.1 The manufacturer’s name and physical address of the principal facility that 3.6.3.2 controls the design and quality of the article;
A statement of conformance from the CAA certifying it has determined 3.6.3.3 that the applicant’s article meets the FAA’s applicable TSO pursuant to § 21.621(a)(2)(i);
A copy of the technical data and other documents required by the TSO; 3.6.3.4 Any requested deviations from the TSO (refer to paragraph 3.11 of this 3.6.3.5 AC); and Any NTF data for which you seek acceptance, if specifically permitted by 3.6.3.6 the applicable bilateral agreement.
3.7 Use of Subject Matter Experts in the TSOA Process.
Any person who has the expertise to review TSO data can assist a TSO applicant in drafting its statement of conformance. However, only the applicant can make the statement of conformance.
3.8 Provide Installation Instructions and Limitations.
The TSO installation instructions provide information for proper integration or attachment of the article into the product. Installation instructions are typically
3-5 a step-by-step procedure for use by the installer to accomplish this goal. A TSO installation limitation is information that helps an installer determine the applicability (that is, eligibility) of the article to be installed in the product. The TSO installation limitations ensure that the article, when installed according to the installation instructions, continues to meet the requirements of the TSO MPS. Note that since the TSOA does not convey product installation approval, the TSO installation instructions and limitations do not convey what is required to have a compliant installation per the applicable airworthiness requirements of the product.
As an applicant for a TSOA, you must establish and provide installation instructions, 3.8.1 limitations, and maintenance instructions to the ACO and the installer (pursuant to § 21.50 and § 43.13).
You must provide enough detail in the installation limitations for the installer to 3.8.2 determine if the TSO article is compatible with the product and with all foreseen equipment and systems with which the article is intended to interface. For example, the limitations section for avionics TSO articles should clearly state the software and hardware design assurance levels as well as interoperable versions/revisions so the installer can determine compatibility of the TSO article with the product it is installed in (pursuant to § 21.50).
You may choose to limit the TSO article to interface only with specific components or 3.8.3 equipment once installed in the product. Identify and describe any unique aspects of the TSO article, including all NTFs and any incomplete TSO article instructions and limitations, in the limitations section.
If you do not demonstrate by lab or simulator testing and/or by analysis that the 3.8.4 TSO article will perform its intended function when installed, list additional testing requirements in the installation instructions or procedures. The additional testing requirements should allow the installer to demonstrate that the article is compatible with the equipment it interfaces with, and will continue to meet the requirements of the TSO after installation.
Typically the TSO also requires that installation instructions, limitations, and 3.8.5 maintenance instructions be furnished with each article that is shipped. Generally, if a group of articles is being shipped to one location, it is acceptable to make one set of the documentation available for the entire group of identical articles. This is an acceptable practice unless the recipient wants a copy of the documentation for each article.
You must include in your installation and limitations documentation (pursuant 3.8.6 to § 43.13(a)):
Basic instructions on how your article is intended to be installed in the 3.8.6.1 product;
Specific steps to be followed for the integration of the article into the 3.8.6.2 product;
3-6 Tests or inspections to help verify that the article is installed correctly; 3.8.6.3 All installation and additional requirements for the installation of your 3.8.6.4 article necessary to ensure that your article will continue to meet the MPS specified in the TSO once installed in a product; and Details of any deviations per para 3.11.7 of this AC, as applicable. 3.8.6.5 In cases where you know the configuration of the product into which your article will 3.8.7 be installed, identify the limitations that need specific attention. Although the installation of the article is not your responsibility, we encourage you to develop a thorough set of installation instructions and limitations to help ensure your article will be installed and operated in a manner that continues to meet the TSO and the anticipated airworthiness regulations.
3.9 Provide Maintenance Instructions for the Article.
Most TSO require you to develop and submit maintenance instructions for approval.
Instructions for Continued Airworthiness (ICA) are required for all products. You must submit TSO maintenance instructions that will allow the article to continue to meet the TSO requirements after it is installed (for the product to comply with § 43.13(a)).
These are not necessarily the same requirements for the product, but your instructions can be used by the type certificate (TC)/supplemental type certificate (STC) applicant as the basis for them to meet their responsibilities for ICA at the product level. You should submit the TSO maintenance instructions to the ACO with the TSO application package. Include in your maintenance and limitation instructions, as appropriate:
Inspection intervals; 3.9.1 Inspection procedures; 3.9.2 Recommended service life; 3.9.3 Wear limits; 3.9.4 Cleaning instructions; 3.9.5 Basic maintenance instructions; 3.9.6 Calibration information; 3.9.7 Information on any special tools required; 3.9.8 Acceptable repairs and repair procedures; and 3.9.9 Any other information necessary to maintain compliance with the TSO while in service. 3.9.10
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3.10 Submit Open Problem Reports (OPR).
If your TSOA article provides software or Airborne Electronic Hardware (AEH) functionality, you must submit a summary to the ACO of software or airborne electronic hardware problems (or potential problems) that have been identified, but not yet resolved. OPR with a potential safety effect, or which result in noncompliance with the TSO, must be corrected before approval. You should provide an OPR summary with functional impacts to applicants for installation approval of the article:
A sufficient description should be provided for proper assessment; 3.10.1 Any OPRs with potential safety impact should be corrected; 3.10.2 OPR information should be provided in the installation manual or supplemental data; 3.10.3 There should be a means for updating OPR summary if necessary; 3.10.4 The TSOA holder should provide contact information in case installer needs more 3.10.5 information;
The TSOA holder should have a means to accept problems reported from the field. 3.10.6 Note 1: This may require the ACO to review your process for classifying OPR or confirm the ACO agrees with each OPR classification.
Note 2: You must have a means for transmitting the summary of OPR to the installation approval holder and facilitate updates in case additional OPR are discovered after the TSOA is issued. You must have a means of entering problems reported from the installation approval holders and operators into a problem reporting system for tracking and disposition, and for providing OPR support to the installation approval holder.
3.11 Requesting Approval to Deviate From a TSO (§ 21.618).
A deviation may be granted by the FAA if the applicant demonstrates that factors or 3.11.1 design features provide an equivalent level of safety (ELOS) to compensate for the requirement from which a deviation is requested. A deviation request is specific to the article approval and must be re-submitted for new TSOA or LODA applications. For example, the FAA might approve a deviation to your TSOA for one particular article.
You cannot use that same deviation approval for another TSOA application without requesting another deviation from the MPS.
As an applicant for a TSOA, if you want to deviate from the TSO you must submit a 3.11.2 deviation request to the ACO regardless of the significance of the TSO requirement from which you want to deviate. For example, we require applicants to receive a deviation approval when they propose to use a version of an industry standard later than the one referenced in the specific TSO.
3-8 To receive our approval for a deviation, you must show that compensating features or 3.11.3 factors provide an equivalent level of safety (ELOS) to the TSO performance requirement(s) from which you propose to deviate.
We evaluate your deviation request, and approve the deviation if an ELOS can be 3.11.4 assured. The deviation approval may identify limitations for the approval, which you should consider when making subsequent design changes to ensure the limits continue to be met.
We encourage you to discuss and coordinate the deviation proposal with 3.11.4.1 the ACO before you submit your official deviation request. Discuss the application with your ACO to ensure you do not perform testing or analysis that we may not approve as a sufficient means to substantiate the ELOS. These discussions usually help establish agreement on whether your proposal establishes an ELOS and can save you significant time and resources. Do not consider discussions to be binding. We will evaluate your official deviation request once we receive it and we will respond in writing.
If you are applying for a LODA, we encourage you to have an unofficial 3.11.4.2 dialogue with the CAA. The CAA can coordinate with the FAA to ensure you do not perform testing or analysis that we may not approve as adequate for substantiating the ELOS. These discussions usually help establish agreement on whether your proposal establishes an ELOS and can save you significant time and resources. Do not consider discussions to be binding. We will evaluate the official deviation request once we receive it.
Substantiating the ELOS. 3.11.5 Ensure your deviation request includes substantiating data that specifically covers the compensating factors or features. The proposed TSO deviation must clearly establish an ELOS to the TSO.
Marking the Article for Approved Deviations (pursuant to § 21.618). 3.11.6 When granted a deviation for your article, you must mark the article in accordance with the instructions in the ACO letter that granted the deviation.
Documenting Details of an Approved Deviation. 3.11.7 When you are granted a deviation you must list the specific details of the deviation in your installation manual. This is necessary to alert installers to evaluate the article installation or operational limitations affected by the deviations. Describe the details of all deviations and document all known impacts to performance and functionality resulting from a deviation.
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3.12 Roles of the FAA and Applicant.
We coordinate between the ACO and the Manufacturing Inspection District Office (MIDO) to help you, the applicant, produce TSO articles according to the approved design. Approving a TSOA application requires the ACO to approve the design and the MIDO or Manufacturing Inspection Satellite Office (MISO) to approve the production system. A LODA is an FAA design approval only. Approving a LODA application requires the ACO to approve the design of the foreign-manufactured articles. The applicable CAA issues the corresponding production approval and oversees the production system. Figure 3-1 details the basic roles of the FAA and applicant in the TSO process.
3-10 Figure 3-1. Basic Roles of the FAA and Applicant in the TSO Process * Applicant AIR-100 ACO MIDO Control the design and quality of the article Show compliance with applicable TSO standard Set up and maintain a QS that meets § 21.607 or is in accordance with bilateral agreement Provide a statement of conformance to the applicable TSO(s) Request approval to deviate from TSO Establish and provide installation instructions, operational limitations, OPR summary, and maintenance instructions Provide maintenance instructions and installation limitations to each person who receives articles, to ensure the article continues to meet the MPS of the TSO after installation Mark each article according to § 45.15(b) and as specified in each applicable TSO Report service difficulties pursuant to § 21.3 Submit TSOA’s minor changes to the ACO Submit to the FAA document describing how its organization will ensure compliance Develop PSP with ACO as applicable Administer TSO program policy Develop and issue new TSO Determine when TSO require revisions Cancel obsolete TSO Determine if all TSOA for a particular TSO must be withdrawn, and publish intentions of withdrawal in the Federal Register before the withdrawal. If it is determined necessary, the process defined in the appropriate paragraph of Order 8150.1 will be followed Grant/deny deviation requests not delegated to the ACO Maintain records for TSO, including canceled TSO Process TSOA applications and LODA applications from a CAA, if applicable Recommend approval or denial of deviations to the TSO to AIR-100 Grant/deny deviations that Order 8150-1D or a specific TSO has delegated to the ACO Coordinate with MIDO (TSOA) or follow the procedures defined in the bilateral agreement (LODA) before issuing TSOA/LODA letters.
Witness various functions if deemed necessary (refer to § 21.610) Find that the article design complies with the applicable TSO Send applicant TSOA, LODA, or denial letter Investigate reports of service difficulties and noncompliance Submit enforcement reports when holders do not comply with part 21, subpart O As applicable, work with applicants to develop Partnership for Safety Plans (PSP)
Verify production system produces articles that conform to the approved design Approve the quality system Issue TSOA article production approval letter to ACO Conduct surveillance at the TSOA holder’s and supplier’s facilities, both domestic and foreign, if appropriate.
Investigate service difficulty reports and nonconformities.
Submit enforcement reports when holders do not comply with part 21, subpart O
* Refer to applicable TSO and part 21, subpart O, for further details.
4-1 CHAPTER 4. TSOA AND LODA HOLDER RESPONSIBILITIES
4.1 Continue to Meet the Requirements of the TSO.
Pursuant to § 21.616, as the TSOA or LODA holder, you must:
Amend the document required by § 21.605 as necessary to reflect changes in the 4.1.1 organization and provide these amendments to the FAA;
Maintain a quality system in compliance with the data and procedures approved for the 4.1.2 TSO authorization;
Ensure that each manufactured article conforms to its approved design, is in a condition 4.1.3 for safe operation, and meets the applicable TSO;
Mark the TSO article for which an approval has been issued. Marking must be in 4.1.4 accordance with 14 CFR part 45, including any critical parts;
Identify any portion of the TSO article (e.g., sub-assemblies, component parts, or 4.1.5 replacement articles) that leave the manufacturer's facility as FAA approved with the manufacturer's part number and name, trademark, symbol, or other FAA approved manufacturer's identification;
Have access to design data necessary to determine conformity and airworthiness for 4.1.6 each article produced under the TSO authorization. The manufacturer must retain this data until it no longer manufactures the article. At that time, copies of the data must be sent to the FAA.
Retain the TSO authorization and make it available to the FAA upon request; and 4.1.7 Make available to the FAA information regarding all delegation of authority to 4.1.8 suppliers.
Other countries follow requirements of bilateral agreements, if applicable. 4.1.9
4.2 How to Mark Each Article.
Mark each article pursuant to § 21.616(d) and § 45.15(b), and as specified in the TSO.
Before you ship any article, you must determine that it conforms to its approved design 4.2.1 and mark it with all the information required by § 21.616(d), which includes the specific TSO for which the authorization was granted. You must also mark the article with all specific marking requirements as called out in the TSO for which authorization was issued and as described in paragraphs 4.2.4 and 4.2.5 of this AC. Be sure to review appendices in the TSO, as they may contain additions or exceptions to other marking requirements contained in a referenced industry document (such as Society of
4-2 Automotive Engineers (SAE) documents, aerospace standards (AS), or RTCA, Inc.
(RTCA) documents).
The marking must be permanent and legible. The marking must be accessible (without 4.2.2 the use of tools) in a location where it is easily readable and not easily erased or disfigured. If you receive information about your in-service articles that the TSO markings are missing or can no longer be read, you must investigate the cause and make any design changes necessary to resolve the issue.
When you believe an article is impractical to mark (for example, because of size or 4.2.3 space limitations), you must request a deviation, unless the specific TSO provides explicit alternative marking instructions.
Electronic part marking that identifies the article by electronically embedding the 4.2.4 identification within the hardware component itself (using software) may be used instead of marking the article on the equipment nameplate. If electronic marking is used, it must be readily accessible without the use of special tools or equipment.
Electronic marking of an article is acceptable when the information provided by an electronic identification query system is stored in non-volatile memory. The electronic identification system must be verifiable on board the aircraft, when the aircraft is on the ground at any geographic location, and must provide the specific information required by § 45.15. Ensure that the installation instructions include instructions and technical data needed to facilitate electronic part marking display on the aircraft.
Refer to paragraph 5.4 of this AC for further marking information on multiple TSO 4.2.5 articles.
Refer to paragraph 5.3 of this AC for further marking information on incomplete TSO 4.2.6 articles.
4.3 Report Service Difficulties Pursuant to § 21.3.
As a TSOA holder, you are required by § 21.3(b) to report to us any defect in your 4.3.1 article that you have determined could result in any of the occurrences listed in § 21.3(c). These occurrences include, but are not limited to:
Fires; 4.3.1.1 Engine exhaust system failures; 4.3.1.2 Toxic or noxious gases in the crew compartment or passenger cabin; 4.3.1.3 Malfunctions, failures, or defects in the propeller control system; 4.3.1.4 Flammable fluid leakage; 4.3.1.5 Structural or material brake system failures; 4.3.1.6
4-3 Malfunctions, failures, or defects in the flight control system including 4.3.1.7 interference with normal control; and Malfunctions or failures of attitude, airspeed, or altitude instruments. 4.3.1.8 Note: Review § 21.3(c) for the complete and accurate list of your responsibilities.
If we determine during an accident investigation or service difficulty that your article is 4.3.2 unsafe, you must report to us at our request any results you find or actions you plan to take to correct the deficiencies. You will also have to submit to us any data we need to help the FAA issue an airworthiness directive (pursuant to § 21.3).
4.4 Design Changes.
As a TSOA holder, you are responsible for any design changes you make to your article 4.4.1 and for updating the descriptive and substantiation data. Design changes to your article are classified as either minor or major. We require that you evaluate all design changes to determine if they are minor or major changes.
Pursuant to § 21.601, it is the responsibility of the TSOA holder or LODA holder to 4.4.2 control the design relative to the applicable TSO requirements, including all parts, processes, or services procured from an outside source. Similarly, it is the responsibility of the TC/STC holder to ensure the TSO articles that have undergone design changes continue to meet the applicable airworthiness requirements of the aircraft.
Minor Design Changes Under a TSOA. 4.4.3 We permit TSOA holders to make minor design changes to their articles without further approval. However, all minor design changes must be substantiated to show compliance with the applicable TSO MPS requirements (pursuant to § 21.619(a)). We encourage you to propose to your ACO what constitutes a minor change, including the changes made by your suppliers, for the particular TSO article being manufactured and work with your ACO to establish a mutually agreed upon process for managing minor design changes. Sometimes minor changes may require significant substantiation (including testing) to ensure the article still meets the TSO requirements. However, unless the change results in a “substantially complete investigation” to the TSO, it can be classified as minor pursuant to § 21.619(a). Note that a major/minor design change classification under § 21.619(a) or (b) is made at the article level relative to the TSO standard and should not be confused with a major/minor design change classification under § 21.93. Design change classifications under § 21.93 are made at the product level.
We encourage you to use a partnership for safety plan to formalize the 4.4.3.1 agreement discussed in 4.4.3.1 with your ACO. You can find more information on this process in the FAA and Industry Guide to Product
4-4 Certification. The manufacturer must maintain and submit to the FAA, on request, minor change substantiation data (pursuant to § 21.619(a)).
The article model and/or part number are used for configuration 4.4.3.2 management at the aircraft level. You should change the part number of any article where a minor change to a previously manufactured article may affect the interchangeability at the product level, the use or installation of the article, or the minimum performance standards specified in the TSO.
Update any associated documentation, such as the installation instructions, to identify the difference between the previous and new part number versions of the article.
Pursuant to § 21.619(a), you must substantiate and document all minor 4.4.3.3 design changes. You must notify your ACO within the timeframe agreed upon with them. We recommend the data be submitted before shipping any articles. This will prevent you from distributing potentially noncomplying articles in the event the ACO finds that a minor change claim is improperly substantiated. You must state in your minor change notification letter that the changed article complies with the TSO. This statement reaffirms your compliance with part 21, subpart O. You can send this letter to the ACO by email.
If we determine a minor design change submittal is not sufficiently or 4.4.3.4 properly substantiated, you must provide additional substantiation or other data as requested by your ACO. This could require you to retest the article to show compliance with the TSO standard. If, after review of the substantiation, the ACO determines that the article no longer meets the TSO MPS, you must immediately stop marking and shipping any changed articles and comply with the TSO requirements.
If we determine a minor design change is really a major design change, 4.4.3.5 as defined in § 21.619(b), you must immediately stop marking and shipping any changed articles and comply with the criteria for major design changes.
Major Design Changes Under a TSOA. As stated in § 21.619(b), the FAA requires a 4.4.4 new TSO application for all major design changes to TSO articles under a TSOA.
If the applicable TSO is revised while the application is being evaluated, 4.4.4.1 you should provide an OPR summary with functional impacts to applicants for installation approval of the article;
A sufficient description should be provided for proper assessment; 4.4.4.2 Any OPRs with potential safety impact should be corrected; 4.4.4.3 OPR information should be provided in the installation manual or 4.4.4.4 supplemental data;
4-5 There should be a means for updating OPR summary if necessary; 4.4.4.5 The TSOA holder should provide contact information in case installer 4.4.4.6 needs more information; and The TSOA holder should have a means to accept problems reported from 4.4.4.7 the field.
Only need to demonstrate compliance with the TSO in effect at the time of 4.4.4.8 the original application, not the revised TSO.
The ACO can give up to a 6 month relief period to applicants with 4.4.4.9 pending applications provided the specific TSO being applied for contains provisions for doing so. If the applicant does not submit a complete application within this time, it must comply with the most recent TSO version.
Note: Some revised TSOs may contain a statement that the older version of the TSO will remain effective for a period of months after a revision becomes effective. During this time, the ACO may accept applications for either version of the TSO.
Design Changes Under a LODA. 4.4.5 Design changes to articles that have been issued a LODA are subject to the requirements defined in the applicable bilateral agreement. Generally, when the CAA considers a design change minor, it is approved without any FAA involvement. Design changes the CAA considers major require the LODA holder to apply for a new LODA.
Design Change by a Person Other Than the Manufacturer - TSOA and LODA. 4.4.6 Pursuant to § 21.619(c), we permit design changes to a TSO article by a person other than the original manufacturer who holds the TSO authorization, such as the product operator, the installer of the article, or the maintenance personnel. If the person seeking approval is another article manufacturer (refer to § 21.601(b)(5)), they must apply under a separate TSOA or LODA and obtain approval before modifying the article. The article may also be altered as part of an installation in an aircraft or engine, and approved under part 43 or the applicable airworthiness regulations in 14 CFR parts 23, 25, 27, 29, 31, 33, and 35. In all cases, the article must be permanently marked to indicate it has been modified.
The determination of whether a design change, repair, or alteration is major or minor 4.4.7 varies, and depends on which FAA approval is being affected. These changes are classified differently within their specific regulatory basis, and this classification depends on whether the FAA approval is a TSOA, STC, repair, or alteration. Minor changes under a TSOA may be a major change for other types of FAA approval and vice versa. Regardless of the classification of the modification, all modifications must be substantiated relative to the applicable requirements (pursuant to § 21.619).